Firewalls in Atrial Myocytes
published: Nov. 27, 2007, recorded: October 2007, views: 3924
Report a problem or upload filesIf you have found a problem with this lecture or would like to send us extra material, articles, exercises, etc., please use our ticket system to describe your request and upload the data.
Enter your e-mail into the 'Cc' field, and we will keep you updated with your request's status.
Atrial myocoytes play a prominent role in the generation of heart beats. Their contraction is controlled by Calcium signals that emerge at the cellular periphery and then proceed centripetally to engage the force-generating myofilaments. Experiments have demonstrated that these initial signals need to overcome a barrier just below the cell membrane before they move inward. Since atrial myoctes lack transverse tubules that transmit external signals to the cell interior as e.g. in ventricular myocytes, such a firewall represents a crucial determinant of atrial dynamics. For instances, it allows atrial myocytes to fine tune their responses to a wide range of vital stimuli. Here, we present a computationally advantageous model to investigate the mechanisms that give rise to these graded centripetal signals. Our framework takes into account the three dimensional organisation of atrial myocytes, especially the spatially restricted release of Calcium from internal storage compartments. We employ a fire-diffuse-fire (FDF) model to examine the spatio-temporal patterns and to probe the dependence of wave propagation on physiologically relevant parameters. Mimicking an excitable medium, the FDF approach reflects the significance of noise in intracellullar Calcium dynamics. The explicit construction of the corresponding Green's function allows for a detailed analysis.
Link this pageWould you like to put a link to this lecture on your homepage?
Go ahead! Copy the HTML snippet !